freebsd-nq/lib/libc/sys/sigsuspend.2

.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)sigsuspend.2	8.2 (Berkeley) 5/16/95
.\" $FreeBSD$
.\"
.Dd May 16, 1995
.Dt SIGSUSPEND 2
.Os
.Sh NAME
.Nm sigsuspend
.Nd atomically release blocked signals and wait for interrupt
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In signal.h
.Ft int
.Fn sigsuspend "const sigset_t *sigmask"
.Sh DESCRIPTION
The
.Fn sigsuspend
system call
temporarily changes the blocked signal mask to the set to which
.Fa sigmask
points,
and then waits for a signal to arrive;
on return the previous set of masked signals is restored.
The signal mask set
is usually empty to indicate that all
signals are to be unblocked for the duration of the call.
.Pp
In normal usage, a signal is blocked using
.Xr sigprocmask 2
to begin a critical section, variables modified on the occurrence
of the signal are examined to determine that there is no work
to be done, and the process pauses awaiting work by using
.Fn sigsuspend
with the previous mask returned by
.Xr sigprocmask 2 .
.Sh RETURN VALUES
The
.Fn sigsuspend
system call
always terminates by being interrupted, returning -1 with
.Va errno
set to
.Er EINTR .
.Sh SEE ALSO
.Xr sigaction 2 ,
.Xr sigpending 2 ,
.Xr sigprocmask 2 ,
.Xr sigsetops 3
.Sh STANDARDS
The
.Fn sigsuspend
system call is expected to conform to
.St -p1003.1-90 .
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\" Copyright (c) 1983, 1991, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 3. All advertising materials mentioning features or use of this software`
			`.\" must display the following acknowledgement:`
			`.\" This product includes software developed by the University of`
			`.\" California, Berkeley and its contributors.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
Merge from Lite2 onto mainline - - add undelete() and undelete.2 (requires libc minor bump some time) - man page updates 1997-03-11 11:35:56 +00:00			`.\" @(#)sigsuspend.2 8.2 (Berkeley) 5/16/95`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\"`
Merge from Lite2 onto mainline - - add undelete() and undelete.2 (requires libc minor bump some time) - man page updates 1997-03-11 11:35:56 +00:00			`.Dd May 16, 1995`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Dt SIGSUSPEND 2`
			`.Os`
			`.Sh NAME`
			`.Nm sigsuspend`
			`.Nd atomically release blocked signals and wait for interrupt`
Introduce ".Lb" macro to libc manpages. More libraries manpages updates following. 2000-04-21 09:42:15 +00:00			`.Sh LIBRARY`
			`.Lb libc`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SYNOPSIS`
mdoc(7) police: Use the new .In macro for #include statements. 2001-10-01 16:09:29 +00:00			`.In signal.h`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Ft int`
			`.Fn sigsuspend "const sigset_t *sigmask"`
			`.Sh DESCRIPTION`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 09:22:32 +00:00			`The`
			`.Fn sigsuspend`
			`system call`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`temporarily changes the blocked signal mask to the set to which`
			`.Fa sigmask`
			`points,`
			`and then waits for a signal to arrive;`
			`on return the previous set of masked signals is restored.`
			`The signal mask set`
			`is usually empty to indicate that all`
			`signals are to be unblocked for the duration of the call.`
			`.Pp`
			`In normal usage, a signal is blocked using`
			`.Xr sigprocmask 2`
			`to begin a critical section, variables modified on the occurrence`
			`of the signal are examined to determine that there is no work`
			`to be done, and the process pauses awaiting work by using`
			`.Fn sigsuspend`
			`with the previous mask returned by`
Add or correct section number in .Xr. Use .Vt or .Fn instead of .Xr when needed 2003-06-08 10:01:52 +00:00			`.Xr sigprocmask 2 .`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh RETURN VALUES`
			`The`
			`.Fn sigsuspend`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 09:22:32 +00:00			`system call`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`always terminates by being interrupted, returning -1 with`
			`.Va errno`
			`set to`
mdoc(7) police: Er macro usage cleanup. 2000-11-22 16:02:00 +00:00			`.Er EINTR .`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SEE ALSO`
			`.Xr sigaction 2 ,`
Unify cross-references between sigpending(2), sigprocmask(2), and sigsuspend(2), all three of which operate or depend on the process signal mask. Add a missing xref to sigsetops(3), without which the above three syscalls would be useless. 2003-06-24 15:41:19 +00:00			`.Xr sigpending 2 ,`
Sort cross references. 1997-01-20 23:23:22 +00:00			`.Xr sigprocmask 2 ,`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Xr sigsetops 3`
			`.Sh STANDARDS`
			`The`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 09:22:32 +00:00			`.Fn sigsuspend`
			`system call is expected to conform to`
upgrade STANDARDS from POSIX 1003.1-88 to 1003.1-90 using .St macro use ``is expected to conform to'' phrase, not ``conforms to'' Pointed out by: Bruce->NIST-PCTS 1996-12-02 20:03:58 +00:00			`.St -p1003.1-90 .`